Thank you so much Frazer.
As you suggested the drive belt had slipped out as a pulley had moved due to 2 loose bolts and one that had snapped. These were replaced and the car is sorted of those issues now. It cost £81 which didn't upset me. However the drive belt to the left is making a bit of noise. Is there anything to do to quieten this a touch. Perhaps more significantly though on starting up the engine today, twice, the car seemed to croke as if struggling for fuel (I get paranoid the garage did something during the fix) then when it's running it's smooth and powerful and quiet again.
Thanks again, Steve.